Brake ratio change

[jeremiahnz]

Hi, my car was drums all around and converting to disc. I am planning on running unboosted and then change the pedal ratio.

Is there advice available anywhere on safe modifications to the pedal (ie drilling a new whole), adjusting the cylinder mounting position to maintain a correct angle and acceptable pedal ratios?

I was trying to figure out if this was covered in the car construction manual but couldn’t see if it was covered (will buy it if it is covered)

Thanks

[Chris]

Jan 30, 2020 9:40:15 GMT 12 jeremiahnz said:

Hi, my car was drums all around and converting to disc. I am planning on running unboosted and then change the pedal ratio.

Is there advice available anywhere on safe modifications to the pedal (ie drilling a new whole), adjusting the cylinder mounting position to maintain a correct angle and acceptable pedal ratios?

I was trying to figure out if this was covered in the car construction manual but couldn’t see if it was covered (will buy it if it is covered)

Thanks

Hi Jeremiah

The overarching statement in regards to modifying a pedal is that a pedal assembly sourced from a high volume vehicle and fitted to a low volume vehicle must not be modified in any manner that could result in the weakening of the pedal. 

If you are unsure if drilling the hole will weaken the pedal then I would suggest you take the pedal to your certifier before you drill and show them what you intend to do. They will confirm for you if you are on the right track or they may have an alternative suggestion.

Yes, Chapter 8 of the CCM does contain the requirements for a brake pedal pushrod alignment and also recommended pedal ratios.

Cheers

Chris